import * as readline from "readline"
import chalk from "chalk"
import { saveConfig, loadConfig, getConfigPath } from "../auth/config"

function ask(question: string, defaultValue?: string): Promise<string> {
  const rl = readline.createInterface({ input: process.stdin, output: process.stdout })
  const prompt = defaultValue ? `${question} (${defaultValue})` : question
  return new Promise((resolve) => {
    rl.question(`${prompt}: `, (answer) => {
      rl.close()
      resolve(answer.trim() || defaultValue || "")
    })
  })
}

function askPassword(question: string): Promise<string> {
  const rl = readline.createInterface({ input: process.stdin, output: process.stdout })
  return new Promise((resolve) => {
    rl.question(`${question}: `, (answer) => {
      rl.close()
      resolve(answer.trim())
    })
  })
}

function maskKey(key: string): string {
  if (key.length <= 12) return "sk_***"
  return `${key.slice(0, 5)}...${key.slice(-4)}`
}

export async function loginCommand(): Promise<void> {
  console.log(chalk.blue.bold("\nLLMTune CLI - API Configuration\n"))

  const configPath = getConfigPath()
  const existing = loadConfig()

  const existingKey = (existing.apiKey as string) || ""
  const existingUrl = (existing.apiBase as string) || "https://api.llmtune.io/api/agent/v1"
  const existingModel = (existing.defaultModel as string) || ""

  console.log(chalk.dim(`Config file: ${configPath}\n`))

  const key = await askPassword("Enter your LLMTune API key (sk_...)")
  if (!key) {
    console.log(chalk.red("\nAPI key is required."))
    process.exit(1)
  }

  const apiBase = await ask("API base URL", existingUrl)
  const model = await ask("Default model (leave empty for auto)", existingModel || undefined)

  saveConfig({
    apiKey: key,
    apiBase: apiBase.replace(/\/$/, ""),
    defaultModel: model || undefined,
  })

  console.log(chalk.green("\nConfiguration saved!"))
  console.log(`  API key: ${maskKey(key)}`)
  console.log(`  API base: ${apiBase}`)
  console.log(`  Model: ${model || "auto"}`)
  console.log(chalk.dim(`\nRun ${chalk.bold("llmtune chat")} to start.\n`))
}